Dubbed "Project Fission," the effort will more granularly separate sites and their individual components than is currently the case in Firefox. The goal: Isolate malicious sites and attack code so individual sites cannot wreak havoc in the browser at large, or pillage the browser, the device or the device's memory of critical information, such as authentication credentials and encryption keys.

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"We aim to build a browser which isn't just secure against known security vulnerabilities, but also has layers of built-in defense against potential future vulnerabilities," Nika Layzel, the project tech lead of the Fission team, wrote in a post last week to a Firefox development mailing list. "To accomplish this, we need to revamp the architecture of Firefox and support full Site Isolation." Layzel also published the note as the first newsletter from the Fission engineering group.